A 2-acylamino alcohol derivative, 2-decanoylamino-3-morpholino-1-phenyl-1-propanol (hereinafter referred to as "PDMP"), represented by the following formula: ##STR1## has an activity to control biosynthesis of glycolipids, but the activity is greatly different among its four stereoisomers. Therefore, separation of its optically active isomers is carried out by a method in which decanoylaminoacetophenone is condensed with morpholine by Mannich reaction and then reduced with sodium borohydride to obtain PDMP as a mixture of four stereoisomers, resolution of the diastereomers is effected by a crystallization method and then optical resolution of the racemic compounds is effected by a crystallization method (J. Lipid. Res., 28:565-571 (1987), and Advances in Lipid Research, 26:183-213 (1993)).